Referring to FIG. 1, a conventional cable connecting assembly 1 is used for being connected to a cable 2, and includes a barrel member 11, a tubular member 12, a connect ring 13, a securing member 14, and a seal ring 15. The barrel member 11 has a hollow main body 111 that has opposite first and second end portions 101, 102, and an external threaded portion 112 that extends from the first end portion 101 away from the second end portion 102 and that is for connecting the cable 2 to another cable or other device (not shown). The second end portion 102 is formed with an internal thread 118. The main body 111 and the external threaded portion 112 cooperatively define an accommodating space 110. The tubular member 12 is disposed in the accommodating space 110, and defines a receiving space 120 for receiving the cable 2 therein. The connect ring 13 abuts against an end of the tubular member 12 which is adjacent to the second end portion 102 of the barrel member 11. The securing member 14 has an abutment portion 141 that abuts against the second end portion 102 of the barrel member 11, and a coupling portion 142 that abuts against the connect ring 13 and that is formed with an external thread 143 threadedly engaging the internal thread 118 of the second end portion 102 of the barrel member 11. The abutment portion 141 and the coupling portion 142 of the securing member 14 cooperatively form a through hole 140 in spatial communication with the receiving space 120. The seal ring 15 is sleeved on the coupling portion 142 of the securing member 14, and sealingly contacts an inner surface of the main body 111 of the barrel member 11 and the abutment portion 141 of the securing member 14, so as to prevent water and moisture in the air from entering into the accommodating space 110 and the receiving space 120 through a space between the abutment portion 141 of the securing member 14 and the barrel member 11.
However, when the conventional cable connecting assembly 1 is used for connecting the cable 2 in a relatively humid environment, the conventional cable connecting assembly 1 fails to prevent water and moisture in the air from entering into the accommodating space 110 and the receiving space 120, which may cause damage to the cable 9. Therefore, there is room for improving the structure of the conventional cable connecting assembly 1.